Alternanthera pungens

Alternanthera pungens Kunth in Humboldt, Bonpland & Kunth, Nov. Gen. Sp. 2: 206. 1817; Fl. China @ eFloras.org 5: 427; Fl. North Amer. @ eFloras.org 4: 450; Fl. Pak. @ eFloras.org p. 39; Achyranthes repens L., Sp. Pl. 1: 205. 1753; Alternanthera achyrantha R. Br. Ex Sweet, Hort. Suburb. Lond. 48. 1818; A. repens (L.) Link, Enum. Hort. Berol. Alt. 1: 154. 1821; Telanthera pungens (Kunth) Moq., in DC., Prodr. 13(2): 371.1849.

Prostrate mat-forming annual or perennial herb, rooting at lower nodes, much branched at the base outwards. Stem and branches terete, +/- densely villous with long rigid white hairs, but frequently glabrescent. Leaves opposite, broadly rhomboid-ovate to broadly oval or obovate, 1.5-4.5 cm x 0.3-2.7 cm, unequal in each pair, rounded to subacute at apex with a mucro, attenuate below into a petiole up to 1 cm long, glabrous or thinly appressed-pilose on both surfaces. Inflorescences sessile, axillary, solitary or 2-3 together, globose to shortly cylindrical, 0.5-1.0 cm x 0.5-1.0 cm, stramineous; bracts membranous, white or stramineous, 4-5 mm, lanceolate-ovate, distinctly aristate with excurrent midrib, spiny at apex; bracteoles lanceolate, 3-4 mm, apex acuminate without spine, falling with fruit. Tepals 5, free, extremely dissimilar: 2 outer (abaxial) deltoid-lanceolate, ca. 5 mm, very rigid, 5-nerved below, the intermediate pair of nerves much shorter and finer, outer 2 nerves meet above to join the excurrent, pungently mucronate midrib; inner (adaxial) tepal oblong, flat, 3 mm, blunt and strongly dentate at the apex, 3- nerved below meeting well below apex and apical mucro short and fine; lateral 2 tepals ca. 3 mm long, sharply mucronate, enclosing ovary; abaxial and adaxial tepals with small tuft of white barbed bristles about the basal angles and lateral tepals each with a large tuft about the centre of midrib. Stamens 5, all with anthers; filaments 0.5-0.8 mm long, monoadelphous at the base into a cup; filaments alternate with broad, subquadrate, entire to dentate pseudostaminodes, shorter than filaments; anthers globose. Ovary compressed, squat, narrowed below; style very short, wider than long; stigma capitate. Fruit (utricle) included within tepals, orbicular, rounded, truncate or retuse above, ca. 2 mm long. Seeds discoid ca. 1.2 mm, brown, shining faintly reticulate.

Flowering and Fruiting: January to July
Common Names: Khaki Weed, Khaki Burweed, Paperthorn, Spingflower Alternanthera